With the rapid development of last few decades, more and more people have benefited from mobile communication, but main services provided by mobile communication are still services of telephone and message. With the rapid development of Internet, a large amount of multimedia services emerge concurrently. Obviously, the multimedia services are also required to be supported by mobile communication. Some multimedia service applications provided by Internet, such as mobile video, video broadcast, video conference, education online, and interactive game, require multiple users to receive same data simultaneously. Meanwhile, the mobile video has become a hottest topic in China. In view of conditions of the present applications, methods of implementing of the mobile video are mainly categorized as follows. The first method is a method based on terrestrial broadcast, which includes Digital Video Broadcasting-Handheld (abbreviated as “DVB-H”) technique in Europe, Terrestrial-Digital Multimedia Broadcasting (abbreviated as “T-DMB”) technique in Korea, and MediaFLO technique recommended by Qualcomm of America, etc. The second method is a method based on satellite propagation, which includes Satellite Digital Multimedia Broadcasting (abbreviated as “SDMB”) technique of Europe. The third method is a method based on mobile network, which includes Multimedia Broadcast/Multicast Service (abbreviated as “MBMS”) technique, Broadcast Multicast Service (abbreviated as “BCMCS”) technique, and stream media technique in the 3rd Generation Partnership Project (abbreviated as “3GPP”). Furthermore, there is another important technique, Mobile Broadcast Multicast Service (abbreviated as “BCAST”) standard, which is irrelevant to the Bearer network, and proposed by Open Mobile Alliance (abbreviated as “OMA”).
Among the techniques described above, the MBMS and the BCMCS are to provide point-to-multipoint service in the mobile network where data is sent from a data source to multiple users, in order to efficiently utilize resources of the mobile network. The MBMS service is transmitted between the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (abbreviated as “UTRAN”) and the user terminal in two transmission modes: point-to-multipoint and point-to-point. In the point-to-multipoint mode, same data is sent through a MBMS Point-to-Multipoint Traffic Channel (abbreviated as “MTCH”) Logic Channel, and can be received by all the user terminals which have joined in the multicast service or are interested in the broadcast service. In the point-to-point mode, data is sent through a dedicated service channel, and only received by one user terminal corresponding to the dedicated service channel. However, in the DVB-H technique, plural video channels and audio channels can be simultaneously transmitted to mobile terminals, for the purpose of solving existed problems of power consumption, performance in mobile environment, and flexibility in network design when the digital video broadcasting service is provided to the mobile terminal. In addition, the most important advantage of the DVB-H technique is to provide a business pattern oriented to a horizontal market, with which the content, service, and network layer are divided, and the content provider, broadcast service provider, broadcast network Carrier, mobile network Operator and terminal supplier of the whole industrial chain are enabled to be independent relatively from one another, each of which can dedicate to its own special field and benefit therefrom.
These three techniques are all based on the service layer in the mobile network hierarchical structure. However, those service layers in the three different hierarchical structures of mobile networks described above are converged in the BCAST, thus providing a uniform service platform for users. The hierarchical structure includes a service application module 110, a service distribution and adaptation module 120, a subscription management module 130, and a user terminal 140, as shown in FIG. 1.
These service layer techniques mainly include implementation methods such as methods of audio and video encoding of channel contents, service guide technique, service and content protection technique, service authentication, user management, and charging, etc. The service guide technique is proposed mainly for eliminating the guide date differences among the existed respective different mobile network hierarchical structures in terms of the transmission channel, contents, and format. With the service guide technique, the user is facilitated to view materials of various services, browse video channels, a program list and price list, select and purchase an item of the list, and log in a website to browse webpage, etc. FIG. 2 shows the schematic model of the service guide technique, in which the Service, Schedule, Access, and Purchase Item, etc. represent a service guide fragment, and the line between them represents a quantitative and reference relationship. For example, as shown in FIG. 2, the relationship between the Service and the Schedule is that one Service fragment can be referenced by 0-n Schedule fragments.
In the service guide technique, the definition of each fragment is shown in Table 1. For simplicity, only part of the fragments related to the present invention is listed.
TABLE 1Service guide fragmentDefinitionServiceCollection of ContentsAccessThe Access is associated with Sessiondescription to indicate the distributionmethod; in terms of the user terminal, theAccess indicates how the user can accessand enjoy the program content.ScheduleThe Schedule is a schedule for content orservice.ContentThe Content is the content or programcontained in a service.PurchaseItemThe PurchaseItem is the minimum unit ofservice which can be purchased by the user.. . .. . .
At present, the definition of the PurchaseItem fragment is as shown in Table 2.
TABLE 2Cate-NameTypegoryCardinalityDescriptionData TypePurchaseE0 . . . NPurchase ItemItemfragmentfragmentincludes thefollowingattributes:idversionvalid Fromvalid ToWeightClosedand includes thefollowingsub-elements:ServiceIdRefScheduleIDRefContentIDRefPurchaseItemIDRefNameDescriptionExtensionURLParentalRatingPurchaseDataIDRefDependenciesExclusionsidAM1The uniqueAnyURIidentification ofthe PurchaseItemfragment. . .. . .. . .. . .. . .. . .
wherein E represents an element, A represents an attribute, and M represents mandatory. In Table 2, the attribute “id” of the PurchaseItem fragment, i.e. the identification of the PurchaseItem fragment, is unique identification of the PurchaseItem fragment. This field is generated by the service distribution and adaptation module, adapted to identify the different information fragments in the service guide information, and also serves as the unique identification of the PurchaseItem.
The flow of subscribing a purchase item by a user terminal is shown in FIG. 3. In Block 310, a service distribution and adaptation module generates a PurchaseItem fragment. At 320 and 330, the service distribution and adaptation module sends PurchaseItem fragment identification to a subscription management module, and sends service guide information containing the PurchaseItem fragment to a user terminal. The order of 320 and 330 can be exchanged, or they can be implemented concurrently. In a service management database in the subscription management module, a purchase item is sought and managed based on the PurchaseItem fragment identification. When a user terminal should subscribe for a purchase item, the Block 340 and 350 are implemented, and thus a service request including the PurchaseItem fragment identification which uniquely identifies the purchase item is generated and sent to the subscription management module. The subscription management module searches for the purchase item corresponding to the PurchaseItem fragment identification in the service management database, and accomplishes subscription management for the purchase item according to the PurchaseItem information. The definition of the service request in the prior art includes the contents as shown in Table 3.
TABLE 3Cate-NameTypegoryCardinalityDescriptionData TypePurchase ItemEM1 . . . NItem list toComplexfragmentbeTypesubscribedby userPurchase ItemE1M1UniquelyAnyURIfragmentidentify theidentificationPurchaseItemfragmentandPurchaseItem. . .. . .. . .. . .. . .. . .
The function of identifying a purchase item is realized based on a PurchaseItem fragment identification. Therefore, when the PurchaseItem fragment identification is changed randomly or periodically due to network transmission, the service distribution and adaptation module should send an update message to the subscription management module and the user terminal, as shown at 410 and 420 in FIG. 4. The subscription management module should update the PurchaseItem fragment identification in the service management database according to the update message, while the user terminal updates the PurchaseItem fragment identification information in the service guide information according to the update message. Thus, only if the user terminal sends the service request with the updated PurchaseItem fragment identification to the subscription management module, the subscription management module can find out the corresponding purchase item in accordance with the updated PurchaseItem fragment identification to accomplish the subscription normally.
In real applications, the particular purchase item in the PurchaseItem fragment generally would not change, while the PurchaseItem fragment identification often would change randomly or periodically due to network transmission. Therefore, every time the PurchaseItem fragment identification changes, the service distribution and adaptation module should communicate with the subscription management module, thus causing system resources to be largely wasted, and the subscription management module should update the service management database, thus increasing the load of the subscription management module.